1. Field of the Application
The present invention is directed to inflatable devices, and, specifically, to an inflatable device including two or more fluid chambers that may be fluidly connected by a one way valve such that each chamber may be inflated through a single inlet and exhausted through a single outlet, and such that the amount of fluid in one of the fluid chambers may be adjusted independently of the other.
2. Related Art
Inflatable devices are used in a variety of contexts where buoyancy or a cushioned support is needed, where space is limited, or portability is desired. For example, inflatable mattresses, cushions and other body supports are used for applications such as camping, hospital bedding, and both occasional and everyday bedding in the home. Other uses of inflatable devices may provide support, health, comfort, and safety.
Such inflatable devices are often provided with a mechanism to adjust a degree of inflation of the inflatable device to adjust the amount of support and comfort provided by the inflatable device. However, such inflatable devices typically comprise a single bladder and there is a trade off between the amount of support that the device can provide based on the degree of inflation and the comfort of the device. For example, the device may be fully inflated to the maximum pressure to provide maximum support, but a user may find that the device lacks comfort. In contrast, the user may adjust the inflatable device to a degree of inflation less than a maximum inflation level providing a desired comfort, but the amount of support provided by the device is compromised. For example, the under-inflated inflatable device tends to sag, such as, an inflatable mattress may sag in the middle when supporting the user.
Alternatively, one example of a sleep support system including more than one inflatable chamber for sleep surface adjustment is disclosed in U.S. Pat. No. 6,397,419 B1(the '419 patent). The '419 patent discloses a sleep support system that includes a first fluid chamber positioned side-by-side with a second fluid chamber and separated by a foam center wall. The first fluid chamber and the second fluid chamber are surrounded by an upper wall, lower wall and side walls structure. In addition, the sleep support system comprises a base pad which may be a foam such as an L9 foam or alternatively an additional fluid chamber that is placed below the first and second fluid chambers and that is used to lift the fluid chambers to a level that is substantially even with the top wall of the side walls.
One embodiment of the sleep support system includes one of the fluid chambers coupled to the base pad fluid chamber through an external fluid pump and hand control. In this embodiment, the first fluid chamber can be inflated to its maximum firmness while maintaining the base pad fluid chamber essentially void of any pressurization. Then, a user can flip a switch on the hand control to change the flow of air from the fluid pump so that the fluid pump no longer supplies the fluid to the first fluid chamber, but rather fluid is now directed from the first fluid chamber to the base pad fluid chamber with the idea of maintaining the height of the combination of the first fluid chamber and the base pad fluid chamber, even though the first fluid chamber is reduced in its fluid volume. Similarly, the hand control and fluid pump can be used to cause fluid to flow from the base pad fluid chamber to the first fluid chamber thereby maintaining the height of the overall combination of the first fluid chamber and base pad fluid chamber. With this embodiment of the disclosed sleep support system, the fluid chambers are linked through the external fluid pump such that fluid from one chamber is directed into another chamber to change the pressurization in one chamber. In other words, each chamber cannot be independently pressurized and adjusted.